Analysis of CTG patterns in cases with metabolic acidosis at birth with and without neonatal neurological alterations.

OBJECTIVE: To determine cardiotocographic patterns in newborns with metabolic acidosis, based on clinical signs of neurological alteration (NA) and the need for hypothermic treatment. METHODS: All term newborns with metabolic acidosis in a single center from 2016 to 2020 were included in the study. Three segments of intrapartum CTG (cardiotocography) were considered (first 30 min of active labor, 90 to 30 min before birth, and last 30 min before delivery) and a longitudinal analysis of CTG pattern was performed according to the 2015 FIGO classification. RESULTS: Three hundred and twenty-four neonates with metabolic acidosis diagnosed at birth were divided into three groups: the first group included all neonates with any clinical sign of neurological alteration, requiring hypothermia according to the recommendation of the Italian Society of Neonatology (group TNA-Treated neurological Alteration, n = 17), the second encompassed neonates with any clinical sign of neurological alteration not requiring hypothermia (group NTNA-Not Treated neurological Alteration, n = 83), and the third enclosed all neonates without any sign of clinical neurological involvement (group NoNA-No neurological Alteration, n = 224). The most frequent alterations of CTG in TNA group were late decelerations, reduced variability, bradycardia, and tachysystole. Unexpectedly, from the longitudinal analysis of the CTG, 49% of all cases with metabolic acidosis never showed a pathological CTG with normal trace at the beginning of labor followed by normal or suspicious trace in the final part of labor, the same as in TNA and NTNA groups (10 and 39%, respectively). CONCLUSIONS: CTG has limited specificity in identifying cases of acidosis at birth, even in babies who will develop NA.

Multimodal Model for Predicting Fetal Acidosis in Delivery Room.

In the delivery room, fetal well-being is evaluated through laboratory tests, biosignals like cardiotocography, and imaging techniques such as fetal echocardiography. We have developed a multimodal machine learning model that integrates medical records, biosignals, and imaging data to predict fetal acidosis, using a dataset from a tertiary hospital's delivery room (n=2,266). To achieve this, features were extracted from unstructured data sources, including biosignals and imaging, and then merged with structured data from medical records. The concatenated vectors formed the basis for training a classifier to predict post-delivery fetal acidosis. Our model achieved an Area Under the Receiver Operating Characteristic curve (AUROC) of 0.752 on the test dataset, demonstrating the potential of multimodal models in predicting various fetal outcomes.

Performance of five cardiotocography classification templates in labor: a cohort study.

OBJECTIVE: New guidelines for the interpretation of cardiotocography (CTG) have been presented by FIGO in 2015 (FIGO-15) and by NICE in 2017 (NICE-17) and 2022 (NICE-22) In Sweden, a previous template from 2009 (SWE-09) was replaced in 2017 (SWE-17).The objective of the study was to compare these five different templates for CTG classification regarding sensitivity, specificity, positive and negative predictive values in identifying neonates with acidemia at birth (cord artery pH <7.10). METHODS: This is a historical cohort study including singleton births in Lund November 2015-February 2016, after spontaneous or induced labor at ≥34 completed gestational weeks with validated umbilical cord acid-base samples.Characteristics of cardiotocographic traces during the last hour before birth were reviewed by two independent assessors blinded to outcome. Each template was then used to classify the CTG as normal, suspicious, or pathological. Traces for which classification differed between the two assessors for any of the templates were assessed by a third assessor. The classification by majority (at least 2 of 3) was used for analyses.Main outcome measures were the sensitivity, specificity, and positive and negative predictive values for each template to identify neonates with cord artery pH <7.10 by the classification pathological. In a secondary analysis, these outcome measures were calculated for the classifications suspicious + pathological together. RESULTS: SWE-09 and NICE-22 had significantly higher sensitivity (both 92%; 95% CI 79-98%) than NICE-17 (68%; 51-82%), FIGO-15 (42%; 26-59%) and SWE-17 (39%; 24-57%) to identify neonates with acidemia by the classification pathological. Specificity was significantly higher for SWE-17 (91%; 88-93%), FIGO-15 (90%; 88-93%) and NICE-17 (78%; 74-81%) than for NICE-22 (63%; 59-67%) and SWE-09 (62%; 58-66%). The positive predictive value of a pathological pattern ranged between 15% (SWE-09 and NICE-22) and 24% (FIGO-15), and negative predictive values between 95% (SWE-17) and 99% (SWE-09 and NICE-22). Combining suspicious and pathological patterns increased the sensitivity and decreased the specificity for all templates. CONCLUSIONS: Current CTG interpretation templates either have low sensitivity to identify fetal acidemia or low specificity. Among current guidelines, NICE 2022 had the highest sensitivity to identify neonates with acidemia and is considered the safest current classification system. Efforts to further improve diagnostic precision are warranted.

Admission Cardiotocography and Neonatal Outcomes at a Tertiary Health Facility in Southwestern Nigeria.

BACKGROUND: Admission cardiotocography (CTG), a noninvasive procedure, is used to indicate the state of oxygenation of the fetus on admission into the labor ward. OBJECTIVE: This study assessed the association of admission CTG findings with neonatal outcome at a tertiary health facility. MATERIALS AND METHODS: A prospective, observational study of 206 pregnant women who were admitted into the labor ward with singleton live pregnancies. Information on the demographic characteristics, obstetrics and medical history, admission CTG tracing, and neonatal outcome was obtained using a structured data collection form. Data were analyzed using the SPSS software version 20.0 with the level of significance set at P < 0.05. RESULTS: The admission CTG findings were normal in 73.3%, suspicious in 13.6%, and pathological in 13.1% of the women. The occurrence of low birth weight, special care baby unit (SCBU) admission, asphyxiated neonates, neonatal death, and prolonged hospital admission was significantly more frequent among those with pathological admission CTG results compared with normal and suspicious results (P < 0.05). The incidence of vaginal delivery was more common when the CTG findings were normal, whereas all women with pathological CTG result had a cesarean delivery. CONCLUSION: Admission CTG was effective in identifying fetuses with a higher incidence of perinatal asphyxia. Neonatal outcome such as low birth weight, APGAR score, SCBU admission, and prolonged hospital admission was significantly associated with pathological CTG findings. In the absence of facilities for further investigations, prompt intervention for delivery should be ensured if admission CTG is pathological.

Résumé Contexte:La cardiotocographie d'admission (CTG), une procédure non invasive, est utilisée pour indiquer l'état d'oxygénation du fœtus lors de son admission en salle de travail.Objectif:Cette étude a évalué l'association entre les résultats du CTG à l'admission et l'issue néonatale dans un établissement de santé tertiaire.Matériels et méthodes:Une étude observationnelle prospective portant sur 206 femmes enceintes admises en salle de travail avec des grossesses vivantes uniques. Des informations sur les caractéristiques démographiques, les antécédents obstétricaux et médicaux, le traçage CTG à l'admission et les résultats néonatals ont été obtenues à l'aide d'un formulaire de collecte de données structuré. Les données ont été analysées à l'aide du logiciel SPSS version 20.0 avec le niveau de signification fixé à P <0,05.Résultats:Les résultats du CTG à l'admission étaient normaux chez 73,3 %, suspects chez 13,6 % et pathologiques chez 13,1 % des femmes. La survenue d'un faible poids à la naissance, d'une admission dans une unité de soins spéciaux pour bébés (SCBU), de nouveau-nés asphyxiés, de décès néonatals et d'une hospitalisation prolongée était significativement plus fréquente chez les personnes ayant des résultats CTG d'admission pathologiques par rapport aux résultats normaux et suspects (P < 0,05). L'incidence des accouchements par voie basse était plus fréquente lorsque les résultats du CTG étaient normaux, alors que toutes les femmes présentant un résultat pathologique du CTG avaient accouché par césarienne.Conclusion:L'admission CTG s'est avérée efficace pour identifier les fœtus présentant une incidence plus élevée d'asphyxie périnatale. Les résultats néonatals tels qu'un faible poids à la naissance, le score APGAR, l'admission au SCBU et l'hospitalisation prolongée étaient significativement associés aux résultats pathologiques du CTG. En l'absence de moyens permettant des investigations plus approfondies, une intervention rapide pour l'accouchement doit être assurée si l'admission du CTG est pathologique.

Intrapartum fetal monitoring practices in Norway: A population-based study.

OBJECTIVE: To describe intrapartum fetal monitoring methods used in all births in Norway in 2019-2020, assess adherence to national guidelines, investigate variation by women's risk status, and explore associations influencing monitoring practices. METHODS: A nationwide population-based study. We collected data about all pregnancies with a gestational age ≥ 22 weeks during 2019-2020 from the Medical Birth Registry of Norway. We used descriptive analyses, stratified for risk status, to examine fetal monitoring methods used in all deliveries. Univariable and multivariable logistic regression models were used to determine factors associated with monitoring with cardiotocography (CTG) in low-risk, straightforward births. RESULTS: In total, 14 285 (14%) deliveries were monitored with only intermittent auscultation (IA), 46214 (46%) with only CTG, and 33417 (34%) with IA and CTG combined. Four percent (2 067/50 533) of women with risk factors were monitored with IA only. Half (10589/21 282) of the low-risk women with straightforward births were monitored with CTG. Maternal and fetal characteristics, size of the birth unit and regional practices influenced use of CTG monitoring in this group. CONCLUSIONS: Most births are monitored with CTG only, or combined with IA. Half the women with low-risk pregnancies and straightforward births were monitored with CTG although national guidelines recommending IA.

Rapid detection of fetal compromise using input length invariant deep learning on fetal heart rate signals.

Standard clinical practice to assess fetal well-being during labour utilises monitoring of the fetal heart rate (FHR) using cardiotocography. However, visual evaluation of FHR signals can result in subjective interpretations leading to inter and intra-observer disagreement. Therefore, recent studies have proposed deep-learning-based methods to interpret FHR signals and detect fetal compromise. These methods have typically focused on evaluating fixed-length FHR segments at the conclusion of labour, leaving little time for clinicians to intervene. In this study, we propose a novel FHR evaluation method using an input length invariant deep learning model (FHR-LINet) to progressively evaluate FHR as labour progresses and achieve rapid detection of fetal compromise. Using our FHR-LINet model, we obtained approximately 25% reduction in the time taken to detect fetal compromise compared to the state-of-the-art multimodal convolutional neural network while achieving 27.5%, 45.0%, 56.5% and 65.0% mean true positive rate at 5%, 10%, 15% and 20% false positive rate respectively. A diagnostic system based on our approach could potentially enable earlier intervention for fetal compromise and improve clinical outcomes.

Antenatal cardiotocography in primary midwife-led care: a budget impact analysis.

OBJECTIVES: In many countries, the healthcare sector is dealing with important challenges such as increased demand for healthcare services, capacity problems in hospitals and rising healthcare costs. Therefore, one of the aims of the Dutch government is to move care from in-hospital to out-of-hospital care settings. An example of an innovation where care is moved from a more specialised setting to a less specialised setting is the performance of an antenatal cardiotocography (aCTG) in primary midwife-led care. The aim of this study was to assess the budget impact of implementing aCTG for healthy pregnant women in midwife-led care compared with usual obstetrician-led care in the Netherlands. METHODS: A budget impact analysis was conducted to estimate the actual costs and reimbursement of aCTG performed in midwife-led care and obstetrician-led care (ie, base-case analysis) from the Dutch healthcare perspective. Epidemiological and healthcare utilisation data describing both care pathways were obtained from a prospective cohort, survey and national databases. Different implementation rates of aCTG in midwife-led care were explored. A probabilistic sensitivity analysis was conducted to estimate the uncertainty surrounding the budget impact estimates. RESULTS: Shifting aCTG from obstetrician-led care to midwife-led-care would increase actual costs with €311 763 (97.5% CI €188 574 to €426 072) and €1 247 052 (97.5% CI €754 296 to €1 704 290) for implementation rates of 25% and 100%, respectively, while it would decrease reimbursement with -€7 538 335 (97.5% CI -€10 302 306 to -€4 559 661) and -€30 153 342 (97.5% CI -€41 209 225 to -€18 238 645) for implementation rates of 25% and 100%, respectively. The sensitivity analysis results were consistent with those of the main analysis. CONCLUSIONS: From the Dutch healthcare perspective, we estimated that implementing aCTG in midwife-led care may increase the associated actual costs. At the same time, it might lower the healthcare reimbursement.

How does the use of continuous electronic fetal monitoring influence women's experiences of labour? A systematic integrative review of the literature from high income countries.

BACKGROUND: A variety of technologies are used to monitor fetal wellbeing in labour. Different types of fetal monitoring devices impact women's experiences of labour and birth. AIM: This review aims to understand how continuous electronic fetal monitoring (CEFM) influences women's experiences, with a focus on sense of control, active decision-making and mobility. METHODS: A systematic search of the literature was conducted. Findings from qualitative, quantitative and mixed methods studies were analysed to provide a review of current evidence. FINDINGS: Eighteen publications were included. The findings were synthesised into three themes: 'Feeling reassured versus anxious about the welfare of their baby', 'Feeling comfortable and free to be mobile versus feeling uncomfortable and restricted', and 'Feeling respected and empowered to make decisions versus feeling depersonalised with minimal control '. Women experienced discomfort and a lack of mobility as a result of some CEFM technologies. They often felt anxious and had mixed feelings about their baby's welfare whilst these were in use. Some women valued the data produced by CEFM technologies about the welfare of their baby. Many women experienced a sense of depersonalisation and lack of control whilst CEFM technologies were used. DISCUSSION: Fetal monitoring technologies influence women's experiences of labour both positively and negatively. Wireless devices were associated with the most positive response as they enabled greater freedom of movement. CONCLUSION: The design of emerging fetal monitoring technologies should incorporate elements which foster freedom of movement, are comfortable and provide women with a sense of choice and control. The implementation of fetal monitoring that enables these elements should be prioritised by health professionals.

Transcutaneous Discrimination of Fetal Heart Rate from Maternal Heart Rate: A Fetal Oximetry Proof-of-Concept.

Intrapartum care uses electronic fetal heart rate monitoring (EFHRM) for over 50 years to indirectly assess fetal oxygenation. However, this approach has been associated with an increase in cesarean delivery rates and limited improvements in neonatal hypoxic outcome. To address these shortcomings, a novel transabdominal fetal pulse oximeter (TFO) is being developed to provide an objective measurement of fetal oxygenation. Previous studies have evaluated the performance of TFO on pregnant ewe. Building on the animal model, this study aims to determine whether TFO can successfully capture human fetal heart rate (FHR) signals during non-stress testing (NST) as a proof-of-concept. Eight ongoing pregnancies meeting specific inclusion criteria (18-40 years old, singleton, and at least 36 weeks' gestation) were enrolled with consent. Each study session was 15 to 20 min long. Reference maternal heart rate (MHR) and FHR were obtained using finger pulse oximetry and cardiotocography for subsequent comparison. The overall root-mean-square error was 9.7BPM for FHR and 4.4 for MHR, while the overall mean-absolute error was 7.6BPM for FHR and 1.8 for MHR. Bland-Altman analysis displayed a mean bias ± standard deviation between TFO and reference of -3.9 ± 8.9BPM, with limits of agreement ranging from -21.4 to 13.6 BPM. Both maternal and fetal heart rate measurements obtained from TFO exhibited a p-value < 0.001, showing significant correlation with the reference. This proof-of-concept study successfully demonstrates that TFO can accurately differentiate maternal and fetal heart signals in human subjects. This achievement marks the initial step towards enabling fetal oxygen saturation measurement in humans using TFO.

Intrapartum pyrexia, cardiotocography traces and histologic chorioamnionitis: a case-control study.

OBJECTIVES: To compare characteristics of labor, cardiotocography traces, and maternal and neonatal outcomes, in a cohort of pregnancies at term complicated by maternal intrapartum pyrexia, with or without a histologic diagnosis of chorioamnionitis. METHODS: This is a retrospective case-control study including pregnancies at term with detection of maternal intrapartum pyrexia, delivered between January 2020 and June 2021. Cardiotocography traces were entirely evaluated, since admission till delivery, and classified according to the International Federation of Obstetrics and Gynecology (FIGO) guideline. Maternal and neonatal outcomes were also recorded as secondary outcomes. Placentas have been studied according to the Amniotic Fluid Infection Nosology Committee. RESULTS: Forty four patients met the inclusion criteria and were included in the study cohort. There was a significant association between the use of oxytocin augmentation in labor and the histologic diagnosis of chorioamnionitis. A significative recurrence of loss and/or absence of accelerations at the point of pyrexia was also documented in women with histological chorioamnionitis compared to the others. CONCLUSIONS: Chorioamnionitis appears to be associated with myometrial disfunction, as suggested by the increased use of oxytocin augmentation during active labor of women at term with intrapartum pyrexia and histologic diagnosis of chorioamnionitis.

Computer Vision for Identification of Increased Fetal Heart Variability in Cardiotocogram.

INTRODUCTION: Increased fetal heart rate variability (IFHRV), defined as fetal heart rate (FHR) baseline amplitude changes of >25 beats per minute with a duration of ≥1 min, is an early sign of intrapartum fetal hypoxia. This study evaluated the level of agreement of machine learning (ML) algorithms-based recognition of IFHRV patterns with expert analysis. METHODS: Cardiotocographic recordings and cardiotocograms from 4,988 singleton term childbirths were evaluated independently by two expert obstetricians blinded to the outcomes. Continuous FHR monitoring with computer vision analysis was compared with visual analysis by the expert obstetricians. FHR signals were graphically processed and measured by the computer vision model labeled SALKA. RESULTS: In visual analysis, IFHRV pattern occurred in 582 cardiotocograms (11.7%). Compared with visual analysis, SALKA recognized IFHRV patterns with an average Cohen's kappa coefficient of 0.981 (95% CI: 0.972-0.993). The sensitivity of SALKA was 0.981, the positive predictive rate was 0.822 (95% CI: 0.774-0.903), and the false-negative rate was 0.01 (95% CI: 0.00-0.02). The agreement between visual analysis and SALKA in identification of IFHRV was almost perfect (0.993) in cases (N = 146) with neonatal acidemia (i.e., umbilical artery pH <7.10). CONCLUSIONS: Computer vision analysis by SALKA is a novel ML technique that, with high sensitivity and specificity, identifies IFHRV features in intrapartum cardiotocograms. SALKA recognizes potential early signs of fetal distress close to those of expert obstetricians, particularly in cases of neonatal acidemia.

Multicentric intelligent cardiotocography signal interpretation using deep semi-supervised domain adaptation via minimax entropy and domain invariance.

BACKGROUND AND OBJECTIVE: Obstetricians use Cardiotocography (CTG), which is the continuous recording of fetal heart rate and uterine contraction, to assess fetal health status. Deep learning models for intelligent fetal monitoring trained on extensively labeled and identically distributed CTG records have achieved excellent performance. However, creation of these training sets requires excessive time and specialist labor for the collection and annotation of CTG signals. Previous research has demonstrated that multicenter studies can improve model performance. However, models trained on cross-domain data may not generalize well to target domains due to variance in distribution among datasets. Hence, this paper conducted a multicenter study with Deep Semi-Supervised Domain Adaptation (DSSDA) for intelligent interpretation of antenatal CTG signals. This approach helps to align cross-domain distribution and transfer knowledge from a label-rich source domain to a label-scarce target domain. METHODS: We proposed a DSSDA framework that integrated Minimax Entropy and Domain Invariance (DSSDA-MMEDI) to reduce inter-domain gaps and thus achieve domain invariance. The networks were developed using GoogLeNet to extract features from CTG signals, with fully connected, softmax layers for classification. We designed a Dynamic Gradient-driven strategy based on Mutual Information (DGMI) to unify the losses from Minimax Entropy (MME), Domain Invariance (DI), and supervised cross-entropy during iterative learning. RESULTS: We validated our DSSDA model on two datasets collected from collaborating healthcare institutions and mobile terminals as the source and target domains, which contained 16,355 and 3,351 CTG signals, respectively. Compared to the results achieved with deep learning networks without DSSDA, DSSDA-MMEDI significantly improved sensitivity and F1-score by over 6%. DSSDA-MMEDI also outperformed other state-of-the-art DSSDA approaches for CTG signal interpretation. Ablation studies were performed to determine the unique contribution of each component in our DSSDA mechanism. CONCLUSIONS: The proposed DSSDA-MMEDI is feasible and effective for alignment of cross-domain data and automated interpretation of multicentric antenatal CTG signals with minimal annotation cost.

Short-term variation of the fetal heart rate as a marker of intraamniotic infection in pregnancies with preterm prelabor rupture of membranes: a historical cohort study.

INTRODUCTION: Intraamniotic infection (IAI) and subsequent early-onset neonatal sepsis (EONS) are among the main complications associated with preterm prelabor rupture of membranes (PPROM). Currently used diagnostic tools have been shown to have poor diagnostic performance for IAI. This study aimed to investigate whether the exposure to IAI before delivery is associated with short-term variation of the fetal heart rate in pregnancies with PPROM. METHODS: Observational cohort study of 678 pregnancies with PPROM, delivering between 24 + 0 and 33 + 6 gestational weeks from 2012 to 2019 in five labor units in Stockholm County, Sweden. Electronic medical records were examined to obtain background and exposure data. For the exposure IAI, we used the later diagnosis of EONS in the offspring as a proxy. EONS is strongly associated to IAI and was considered a better proxy for IAI than the histological diagnosis of acute chorioamnionitis, since acute chorioamnionitis can be observed in the absence of both positive microbiology and biochemical markers for inflammation. Cardiotocography traces were analyzed by a computerized algorithm for short-term variation of the fetal heart rate, which was the main outcome measure. RESULTS: Twenty-seven pregnancies were categorized as having an IAI, based on the proxy diagnosis of EONS after birth. Fetuses exposed to IAI had significantly lower short-term variation values in the last cardiotocography trace before birth than fetuses who were not exposed (5.25 vs 6.62 ms; unadjusted difference: -1.37, p = 0.009). After adjustment for smoking and diabetes, this difference remained significant. IAI with a later positive blood culture in the neonate (n = 12) showed an even larger absolute difference in STV (-1.65; p = 0.034), with a relative decrease of 23.5%. CONCLUSION: In pregnancies with PPROM, fetuses exposed to IAI with EONS as a proxy have lower short-term variation of the fetal heart rate than fetuses who are not exposed. Short-term variation might be useful as adjunct surveillance in pregnancies with PPROM.

Trauma in pregnancy: A narrative review of the current literature.

INTRODUCTION: Trauma accounts for nearly half of all deaths of pregnant women. Pregnant women have distinct physiologic and anatomic characteristics which complicate their management following major trauma. OBJECTIVE: This paper comprises a narrative review of the most recent literature informing the management of pregnant trauma patients. DISCUSSION: The incidence of trauma during pregnancy is 6-8%. The focus of clinical assessment must be on the mother, starting with the primary survey. During airway management, clinicians should consider early intubation if necessary and utilize gastric tubes to minimize the risk of aspiration. Pregnant women experience progesterone-mediated hyperventilation, and normal PaCO2 levels may portend imminent respiratory failure. Clinicians should utilize left lateral tilt in hypotensive pregnant women to displace the uterus off the inferior vena cava. Ultrasonography is an attractive imaging modality for pregnant women which is specific for ruling in intraabdominal hemorrhage but not sufficiently sensitive to exclude this diagnosis. Clinicians should not hesitate to order computed tomography imaging in unstable patients if there is diagnostic ambiguity. Cardiotocographic monitoring simultaneously assesses uterine contractions and fetal heart rate and should last at least 4 h for pregnant women following even minor abdominal trauma if their fetus has achieved viable gestational age (approximately 24 weeks). In the event of cardiac arrest, peri-mortem cesarean section may improve outcomes for the mother and fetus alike. Unique specific complications include uterine rupture and placental abruption, which require emergent resuscitation and obstetrics consultation for definitive management. Emergency clinicians should maintain a low threshold for transfer to a tertiary care center given correlations between even isolated and relatively minor traumatic injuries with adverse fetal and maternal outcomes. CONCLUSIONS: Trauma is a common cause of morbidity and mortality in pregnant women. Emergency clinicians must understand the evaluation and management of pregnant trauma patients.